The 3 Basic Shapes of Pontoons Designs - Their Pros & Cons
Pontoon Design: There are three primary types of pontoon designs used on current pontoon boats. One is the foam filled (U) shaped pontoon, another is the round baffled single chambered pontoon, and then there is the single round pontoon with several airtight individual compartments. Each and every dealer will have a reason or explanation why the style on their perspective boats is the best. But a better definition of the best could be a lower cost of production, more efficient to operate, easier to repair if necessary, or maybe even the safest. However all the above designs have their own unique advantages and disadvantages..
U shaped foam filled pontoons: The advantage of foam filled logs is primarily the inherent safety of a redundant flotation system that it provides. Foam filled logs also offer manufactures a cost savings in the production of them. For the U shaped pontoons are inherently easier for them to produce and manufacture. Many manufactures also use a thinner gauge material because the foam inserted within reduces or prevents canning that would usually occur with the thin walled U shape. The inserted foam flotation makes it difficult to use baffles in the pontoons so they are not generally used which will also lower costs of manufacturing. Other disadvantages of the U shaped pontoons are the fact that they are generally fairly narrow in width. The width of the pontoon has a direct affect on how it will displace the water and therefore how high above the water it will float. The narrower pontoons along with the additional weight of the foam results in the pontoons that are sitting lower in the water. The additional draft of the pontoons results in more drag and can reduce fuel economy and increased occurrences of hitting underwater obstructions.And should you ever hull the boat and take in water and it remains there over time the foam has a tendency to absorb it and becomes waterlogged. This condition is nearly impossible to repair effectively and poses a serious problem. Though most pontoons have a drain plug on each pontoon to drain accumulated condensation and water intrusion it also means you have to remove the boat from the water. And finally should you ever need to repair a hulled pontoon the most common and best repair, welding is very difficult to achieve because of the inserted insulation and associated heat from the process.
Single Chambered Baffled Round Pontoons: In general round pontoons offer some significant advantages for geometrically a cylinder is the strongest shape that aluminum can be formed into. The symmetrical design means the diameter stays the same regardless where you measure it. The larger the tube is in diameter the more weight it can carry and the more water it can displace. Baffles are usually put in at specific intervals down the length of the pontoon. At the bottom of each baffle there is a void or pass-through purposely left in place which allows them to pressurize equally throughout. Many pontoons of this design also have a drain plug at the back rear bottom to allow drainage of condensation or accumulated water. The repair-ability of this style pontoon is simplified by the fact that once drained it is a relatively simple routine welding repair. The downside of this design however is should you hull a pontoon you'll accumulate water along the entire length of the pontoon. The baffles somewhat limit water accumulation because each section pressurizes individually until it disallows any more water infiltration.
Round Pontoons with Airtight Individual Chambers: These usually feature at least three often more distinct individual chambers per pontoon. They offer all the efficiently and most of the moat repairable of the above baffled style pontoon. The airtight chambers should they be hulled only allow water into the individual chamber that received the damage. The airtight chambers offer outstanding safety due to this compartmentalized design. However this may be the most labor intensive design to produce and manufacture and often reflects accordingly. The only real drawback to this design is should there be water infiltration into the pontoon. The only way to remove or drain it is through a usually small plug at the top of the individual affected chamber usually by siphoning though small hose. It is a slow cumbersome process should a substantial amount of water be involved.
This excerpt is taken from a longer article on http://www.pontoonhouseboatodyssey.com
- Scott Reynolds